rotating electrical machines

Abstract

To provide a rotary electric machine in which cooling of a magnet is improved.SOLUTION: A rotary electric machine comprises: a rotor having a shaft extended along a center shaft; a stator arranged via an air gap on an outer side of a radial direction of the rotor; and a frame housing the stator. The rotor includes: a rotor core; and a plurality of magnets arranged into the rotor core, and extended in a shaft direction. The shaft includes: a first flow path as a flow path of a coolant liquid extended in the shaft direction; and a second flow path penetrated to the outer side of the radial direction from the first flow path. The rotor core includes: a third flow path that communicates with the second flow path and extended in the circumferential direction; a plurality of fourth flow paths that communicate with the third flow path and are extended in the radial direction; and a plurality of fifth flow paths that communicate with the plurality of fourth flow paths, respectively, are extended in the shaft direction, and cool each of the plurality of magnets.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] Conventionally, there are known techniques for cooling magnets provided in the rotor of a rotating electric machine. Patent Document 1 discloses a configuration in which a rotating shaft has a refrigerant passage extending in the axial direction, and a rotor core also has a refrigerant passage extending in the axial direction. In this configuration, the refrigerant passage of the rotating shaft and the refrigerant passage of the rotor core are connected, so that refrigerant supplied from the axial end of the rotating shaft flows into the refrigerant passage of the rotor core, thereby cooling the magnets near the refrigerant passage of the rotor core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-187834 Summary of the Invention [Problem to be solved by the invention]

[0004] A plurality of magnets are arranged circumferentially according to the number of poles of the rotating electric machine. To cool these multiple magnets, a refrigerant flow path in the rotor core is required near each magnet, and the same number of flow paths connecting the refrigerant flow path of the rotating shaft to the refrigerant flow path of the rotor core are also required. For this reason, in the past, the same number of through holes that penetrate the rotating shaft radially from the inside of the refrigerant flow path to the outside were required as the refrigerant flow paths of the rotor core. In this case, if the number of poles of the rotating electric machine changes, the rotating shaft must be changed just to cool the magnets, which increases costs and leaves room for improvement in magnet cooling.

[0005] An object of the present invention is to provide a rotating electric machine with improved cooling of the magnet. [Means for solving the problem]

[0006] A rotating electric machine according to one aspect of the present invention includes a rotor having a shaft extending along a central axis, a stator arranged radially outside the rotor via an air gap, and a frame that houses the stator, wherein the rotor has a rotor core and a plurality of magnets arranged within the rotor core and extending in an axial direction, the shaft has a first flow path that is a flow path for refrigerant liquid extending in the axial direction, and a second flow path that penetrates radially outward from the first flow path, the rotor core has a third flow path that communicates with the second flow path and extends in a circumferential direction, a plurality of fourth flow paths that communicate with the third flow path and extend in a radial direction, and a plurality of fifth flow paths that communicate with each of the plurality of fourth flow paths, extend in the axial direction, and cool each of the plurality of magnets, and the number of the second flow paths is less than the number of the fourth flow paths. Moreover, the circumferential position of the fourth flow passage is shifted from the circumferential position of the second flow passage.

[0007] In the rotating electric machine according to one aspect described above, the third flow passage extends over the entire circumference in the circumferential direction.

[0008] In the rotating electric machine according to the above aspect, a plurality of the third flow passages are arranged in the circumferential direction.

[0009] In the rotating electric machine according to the above aspect, the position where the plurality of fourth flow passages communicate with the plurality of fifth flow passages is the axial center position of the rotor core. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide a rotating electric machine with improved cooling of the coil. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of a motor according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional side view of the motor 100 of FIG. 1 taken along a plane passing through the center axis J and perpendicular to the X axis, as viewed from the -X side. [Figure 3]10 is a cross-sectional side view taken along a line perpendicular to the axial direction and passing through a flow path 131k, as viewed from the -Z side. [Figure 4] FIG. 2 is a perspective view showing an oil flow path in the motor 100. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a rotating electric machine according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0013] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z axis direction is parallel to the axis of the central axis J shown in Figure 1. The Y axis direction is the radial direction relative to the central axis J, which is the up-down direction in Figure 1. The X axis direction is perpendicular to both the Z axis direction and the Y axis direction. In each of the X axis direction, the side indicated by the arrow in the drawing is the positive side, and the opposite side is the negative side.

[0014] In the following description, the positive side (+Z side) in the Z-axis direction will be referred to as "one side," and the negative side (-Z side) in the Z-axis direction will be referred to as "the other side." Note that "one side" and "the other side" are names used merely for the purpose of explanation and do not limit the actual positional relationship or direction. Furthermore, unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) will be referred to simply as "axial direction," the radial direction centered on the central axis J will be referred to simply as "radial direction," and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J, will be referred to simply as "circumferential direction." The side approaching the central axis J in the radial direction will be referred to as "radially inner," and the side away from the central axis J will be referred to as "radially outer."

[0015] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted by less than 45° with respect to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction (Z-axis direction), but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted by an angle of less than 45° with respect to each other.

[0016] First Embodiment FIG. 1 is a perspective view of a motor according to a first embodiment of the present invention. The motor 100 of FIG. 1 is an example of a rotating electric machine. The motor 100 includes a rotor 130 (see FIG. 2) having a shaft 110 extending along a central axis J, and a stator 150 (see FIG. 2) disposed radially outward of the rotor 130 via an air gap. The shaft 110 is rotatable around the central axis J as a rotation axis.

[0017] Motor 100 has a frame 101 that houses stator 150, a bracket 102 arranged on the other axial side of frame 101, a bracket 103 arranged on one axial side of frame 101, and a cover 104 that covers one axial side of bracket 103. Frame 101 has an oil inlet 105 that supplies oil into motor 100. Frame 101 has an oil outlet 106 that discharges oil from inside motor 100. Oil is an example of a refrigerant liquid. In motor 100 of this embodiment, the magnets are cooled by oil, but the rotating electric machine of the present invention may also cool the magnets by a refrigerant liquid other than oil.

[0018] The frame 101 is a cylindrical member with both axial ends open. The frame 101 is made of, for example, die-cast aluminum. The bracket 102 is a plate-like member that closes an opening on the other axial side of the frame 101. The bracket 102 is fixed to the other axial side of the frame 101 by, for example, a bolt. The bracket 102 is made of, for example, die-cast aluminum. The bracket 103 is a plate-like member that closes an opening on one axial side of the frame 101. The bracket 103 is fixed to one axial side of the frame 101 by, for example, a bolt. The bracket 103 is made of, for example, die-cast aluminum. The cover 104 is fixed to one axial side of the bracket 103 by, for example, a bolt. The cover 104 is made of, for example, die-cast aluminum.

[0019] 2 is a side cross-sectional view of the motor 100 in FIG. 1 taken along a plane that passes through the central axis J and is perpendicular to the X-axis, and is viewed from the -X side. The stator 150 has a stator core 151 and coils 152. The stator core 150 is fixed to the frame 101 by, for example, shrink fitting.

[0020] The motor 100 has a bearing 112 and a bearing 113. The other axial end of the shaft 110 is fixed to the inner ring of the bearing 112. The one axial end of the shaft 110 is fixed to the inner ring of the bearing 113. The outer ring of the bearing 112 is fixed to the bracket 102. The outer ring of the bearing 113 is fixed to the bracket 103. The shaft 110 is supported by the bearing 112 and the bearing 113 so as to be rotatable about the central axis J as the rotation axis.

[0021] The frame 101 has a flow path 101a into which oil flows from the oil inlet 105. The flow path 101a extends in the axial direction. The flow path 101a penetrates the frame 101 in the axial direction.

[0022] The bracket 103 has a flow passage 103a penetrating therethrough in the axial direction, the other axial end of which communicates with one axial end of the flow passage 101a.

[0023] Cover 104 has flow path 104a on the +Y side that communicates with one axial end of flow path 103a and extends in the -Y direction. Cover 104 has flow path 104b on one axial end that communicates with the -Y side end of flow path 104a and extends toward the other axial end. Cover 104 has hole 104c on one axial end that communicates with flow path 104b and extends toward the other axial end. Hole 104c has a larger diameter than flow path 104b.

[0024] The shaft 110 has a flow passage 110a that opens on one axial side and extends to the other axial end. One axial end of the shaft 110 overlaps with the hole 104c in a direction perpendicular to the axial direction. The motor 100 has an oil seal 104d at this overlapping position. The oil seal 104d prevents oil leakage from between the hole 104c and the shaft 110. One axial end of the flow passage 110a communicates with the flow passage 104b.

[0025] The shaft 110 has a flow path 110b that communicates with the flow path 110a on one axial side and extends toward the other axial end. The rotor 130 has a rotor core 131 and a magnet 132 (see FIG. 3). The flow path 110b extends toward the other axial end from the axial center position of the rotor core 131. The flow path 110b does not penetrate toward the other axial end. The rotor core 131 has flow paths 131a, 131b, 131c, 131g, 131k, and 131q, which will be described in detail later.

[0026] The oil that flows in from the oil inlet 104 flows through the various flow paths described in detail below, inside the motor 100, and reaches the oil pan 111. The oil in the oil pan 111 is discharged to the outside from the oil outlet .

[0027] 3 is a cross-sectional side view taken along a line perpendicular to the axial direction and passing through flow path 131k, as viewed from the -Z side. Rotor 130 has rotor core 131 and a plurality of magnets 132 disposed within rotor core 131 and extending in the axial direction.

[0028] The shaft 110 has a flow passage 110b that is an oil flow passage extending in the axial direction. The shaft 110 also has a flow passage 110c and a flow passage 110d that penetrate radially outward from the flow passage 110b.

[0029] Flow passage 131a of rotor core 131 communicates with flow passage 110c and extends in the circumferential direction. Flow passage 131c of rotor core 131 communicates with flow passage 131a on the radially inner side and extends radially outward. Flow passage 131k of rotor core 131 communicates with flow passage 131c at the axial center of rotor core 131, extends to both axial sides, and axially penetrates rotor core 131. Flow passage 131k is disposed close to magnet 132 extending in the axial direction, and oil flowing through flow passage 131k cools magnet 132. Oil flows out from both axial ends of flow passage 131k and accumulates in oil pan 111.

[0030] Flow passage 131b of rotor core 131 communicates with flow passage 110d and extends in the circumferential direction. Flow passage 131g of rotor core 131 communicates with flow passage 131b on the radially inner side and extends radially outward. Flow passage 131q of rotor core 131 communicates with flow passage 131g at the axial center of rotor core 131, extends to both axial sides, and axially penetrates rotor core 131. Flow passage 131q is disposed close to magnet 132 extending in the axial direction, and oil flowing through flow passage 131q cools magnet 132. Oil flows out from both axial ends of flow passage 131q and accumulates in oil pan 111.

[0031] In this embodiment, a plurality of flow passages 131a and 131b are provided in the circumferential direction as flow passages that communicate with a flow passage (flow passage 110c or flow passage 110d) that penetrates radially through shaft 110 and extend in the circumferential direction, but the present invention is not limited to this, and a single flow passage that extends around the entire circumferential direction may be used. Flow passage 110c and flow passage 110d are, for example, grooves that are recessed radially outward from the inner circumferential surface of rotor core 131.

[0032] FIG. 4 is a perspective view showing an oil flow path inside the motor 100. As shown in FIG.

[0033] Flow passage 131d of rotor core 131 communicates with flow passage 131a on the radially inner side and extends radially outward. Flow passage 131m of rotor core 131 communicates with flow passage 131d at the axial center position of rotor core 131, extends to both axial sides, and axially penetrates rotor core 131. Flow passage 131m is disposed close to magnet 132 extending in the axial direction, and oil flowing through flow passage 131m cools magnet 132. Oil flows out from both axial ends of flow passage 131m and accumulates in oil pan 111.

[0034] The flow passage 131e of the rotor core 131 has the same configuration as the flow passage 131d. The flow passages 131n and 131p of the rotor core 131 have the same configuration as the flow passage 131m.

[0035] Flow passage 131h of rotor core 131 communicates with flow passage 131b on the radially inner side and extends radially outward. Flow passage 131r of rotor core 131 communicates with flow passage 131h at the axial center of rotor core 131, extends to both axial sides, and axially penetrates rotor core 131. Flow passage 131r is disposed close to magnets 132 extending in the axial direction, and oil flowing through flow passage 131r cools magnets 132. Oil flows out from both axial ends of flow passage 131r and accumulates in oil pan 111.

[0036] The flow passages 131h and 131j of the rotor core 131 have the same configuration as the flow passage 131h. The flow passages 131s and 131t of the rotor core 131 have the same configuration as the flow passage 131r.

[0037] The flow paths 131k, 131m, 131n, 131p, 131q, 131r, 131s, and 131t are arranged at equal intervals in the circumferential direction. The number of the flow paths 131k, 131m, 131n, 131p, 131q, 131r, 131s, and 131t is determined according to the number of the magnets 132. On the other hand, the number of the flow paths 110c and 110d may be determined regardless of the number of magnets, as long as oil can be supplied to the flow paths 110c and 110d.

[0038] According to this embodiment, the oil can be transported by the rotational centrifugal force of the rotor 130, so that the oil can be supplied uniformly in the rotational direction and the magnet 132 can be cooled uniformly in the axial direction.

[0039] Furthermore, according to this embodiment, oil can be supplied to the vicinity of the magnet 132n, so that the magnet can be cooled efficiently.

[0040] Furthermore, according to this embodiment, flow paths 131k, 131m, 131n, 131p, 131q, 131r, 131s and 131t extend in a direction parallel to the extension direction of magnet 132 (longitudinal direction, axial direction of magnet 132), and therefore magnet 132 can be cooled along the axial direction.

[0041] Furthermore, according to this embodiment, the inner side of the coil end of the coil 152 of the stator 150 can be cooled by the oil discharged from both axial ends of the flow paths 131k, 131m, 131n, 131p, 131q, 131r, 131s and 131t.

[0042] Furthermore, according to this embodiment, the flow paths 131k, 131m, 131n, 131p, 131q, 131r, 131s, and 131t can function as flux barriers.

[0043] Furthermore, according to this embodiment, by having flow paths 131a and 131b, even if the number of poles is changed and the number of flow paths for cooling the magnets is changed, there is no need to change shaft 110, which is advantageous in terms of cost.

[0044] Furthermore, according to this embodiment, by providing the flow passages 131a and 131b, it is possible to reduce the number of flow passages that penetrate the shaft 110 in the radial direction, thereby reducing costs.

[0045] Furthermore, according to this embodiment, by providing the flow passages 131a and 131b, the cross-sectional area of ​​the rotor core 131 can be reduced, and the weight of the motor 100 can be reduced.

[0046] Furthermore, according to this embodiment, the flow paths 131a and 131b are provided, so that the inner circumferential side of the rotor core 131 can be cooled and the interference with the shaft 110 can be prevented from decreasing.

[0047] The present invention is not limited to the above-described embodiments, and various improvements and design changes may be made without departing from the spirit of the present invention. In addition, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0048] 100...motor, 101...frame, 110...shaft, 130...rotor, 150...stator

Claims

1. a rotor having a shaft extending along a central axis; a stator disposed radially outside the rotor via an air gap; a frame that houses the stator; Equipped with The rotor has a rotor core and a plurality of magnets disposed within the rotor core and extending in the axial direction, The shaft has a first flow path that is a flow path for refrigerant liquid extending in an axial direction, and a second flow path that penetrates radially outward from the first flow path, the rotor core has a third flow path communicating with the second flow path and extending in a circumferential direction, a plurality of fourth flow paths communicating with the third flow path and extending in a radial direction, and a plurality of fifth flow paths communicating with each of the plurality of fourth flow paths, extending in an axial direction, and cooling each of the plurality of magnets, the number of the second flow paths is less than the number of the fourth flow paths; a circumferential position of the fourth flow path is shifted from a circumferential position of the second flow path; Rotating electric motor.

2. The third flow path extends over the entire circumferential direction. The rotating electric machine according to claim 1 .

3. The third flow passages are arranged in a plurality in the circumferential direction. The rotating electric machine according to claim 1 .

4. The positions at which the plurality of fourth flow paths communicate with the plurality of fifth flow paths are in the axial direction of the rotor core. It is in the central position. The rotating electric machine according to any one of claims 1 to 3.

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